Badio tuning device



June 7, 1927.

W. L. MILLER RADIO TUNING DEVICE 3 Sheets-sheaf 1 Filed Sept. 2. 1925 gnwuloc William L.M|'Her June 7, 1927.

v w. L. MILLER RADIO ruume nsvzca Filed Sept. 2. 1925 3 Sheets-Sheet 2 WW/7770a Pig. 4"

gwoenloc.

l liam L. .Miller June 7, 1927.

W. L. MILLER RADIO 'ruuxgg nhvma 5 Sheets-shat 3 WiHiam LMilleir Filed Sept. 2. 1925 Patented June 7, 1927.

PATENT OFFICE.

WILLIAM L. MILLER, OF ST. PAUL, MINNESOTA.

RADIO TUNING DEVICE.

Application filed September 2, 1925. Serial No. 54,129.

My invention relates to radio tuning devices and has for an. object to provide a device employing a. fixed. inductance coil and a movable inductance coil with means for micrometrically adjusting the relative coupling of said coils.

Another object of the invention is to provide a rotatable support for said movable coil and to provide means for adjusting the position of said movable coil relative to said support. A still further object of the invention rcsides in supporting said movable coil so that the same may be adjustably rotated about two axes .lying at right angles to one another.

One of the features of the invention is to provide the movable coilwith a. shaft on which said coil is fixed for rotation, and to provide a support for said shaft which is itself .mounted upon a shaft positioned at right angles to said first named shaft, and to further provide an operating spindle for said first named shaft which passes'thru said secondshaft. v

A feature-of the invention resides in attaching to said last named shaft a yoke which supports said firstnamed shaft detachably, whereby the movable coil and shaft attached thereto may be conveniently' 1:emovedfrom the device, permitting of interchanging coils.

A still,furtheiflobject'resides ,in; providing. a one hole mounting for the entire device whereby the, fixed coil or the entire structure may. be easily and quickly placed in position, or removed.

Another object of the invention is to provide a gear train fOroperating the first shaft from said spindle whereby said spindle travels at a greater rate of speedthan said first named shaft.

Other objects of the invention reside in the detailed construction of the invention as disclosed in the following specifications and drawings and brought out in the claims.

In the drawings illustrating my invention in one form:

Fig. 1 is a plan sectional view of my invention.

Fig. 2 is a sectional view taken on line 22 of Fig. 1 with portions of the same omitted.

Fig. 3 is a view similar to Fig. 1 showing a modification of the invention.

v Fig. 4 is a view similar to Fig. 2 taken on line 4-4 of Fig. 3.

Fig. 5 is an enlarged sectional view of one form of the operating mechanism of the invention.

'6 is a view similar to Fig. l of another form of the invention.

Fig. 7 is an elevational view taken on line 77 of Fig. 6.

Fig. 8 is an enlarged sectional view of the spindle and mount of the invention.

Fig. 9 is a detail view showing the method of attaching a tubular coil to the mounting.

Fig. 10 is a detail view of another form of coil mounting.

In radio receiving apparatus it is highly desirable to have an inductance coil which may be micrometrically adjusted to vary the inductance in the circuit. This is particularl'y'true in regenerative receiving apparatus using'a tickler coil especially at low wave lengths where the degree of feed back required to produce the best results is very slight. In such cases it is very desirable to have a tickler coil which may have a sufli- "cient number of turns on it and a correspondingly highrvalue of inductance so that sufiicient feed-back may be had for longer wave lengths where a relatively greater amount bf feedgbackris required for best results.

-My invention meets with these requirements in providing an adjusting mechanism which admitsof a considerably more delicate adjustment in one position than in its other positions thereby permitting the movable coil to be wound with a sufiicient number of turns and of correspondingly high inducta'nce value to meet-with the maximum feedback requirements and at the same time to be most accurately or finely'adjustedwhen in its more loosely coupled positions.

The form of the invention shown in Figs. 1 and2 is especially adapted to be mounted on a panel and in these figures I have illustrated a portion of a panel in section which is designated at 10. The invention here illustrated is of the nature of a variocoupler A, which consists of a fixed coil 11 and a movable coil 12. The fixed coil 11 may be of the ordinary type being. a single layer coil 14 wound on an insulating tube 13. A bracket 15 attached to the tube 13 is bolted to the panel 10 by means of small machine screws 16. Althou h I specify a single :2 layer or solenoid nod for em: 14 it can he readily understood that a bank-wound coil or a spider webcoil or the-ordinary. form of basket wound coil or any fiat wound may be used with like effect.

Immediately above the winding-14 0f; the.

coupler A I provide a hollow shaft 17, which passes thru the panel 10, the br aok'eti lfi and ner endof said shaft is placcd a spacer washer 201, which lies adjacent inner surface of the tube 13. Next to this washer is positioned apair of fiber blocks 19 and 20 which are rectan ular in sliape and formed with recesses acapted to fit aboubthe shaft 17. The screws 21 and 22 are screwed into these blocks and serve to hold thesame clamped to said shaft 17. p 7

The movable coil 12 of my: invention is shown in the drawings as being inthe nature of a spider web or flat-wound coil with. the form on which it is made; removed- As a part. of the form a shaft" 231 .en ployed which is constrlnctedof' an insulating material anld overwhichfthe windings of the coil are placed Y the constructionthereof, On removal the remainder of the? form the shaft remains. embedded the coil: and

' upon impregnatingithefcoilint a -suitable insulating-material said shaft' becomes securely'ce'mented to iheQcQiIPrb Qq Coil 12 is supported as follows: Secured o he blocks endQ O een: ha c ew 21 an d 22 are two'arins 2{1}'and 25, which diverge to form a fork. At the ends of. these arms are arranged sockets :26 fit over metallic caps 27 attached to the 'QhdSDf the hfifl 2321 1 P Q I flyfid Lu iperiphery of the "coil 1 12. The: arms are formed; with spring" niaterialiso that' the same frictionally ngage tli'e' caps 2'f and ho d. the 0 .12. e h l fi b n etl p 'n the support". I.

For ae t ng he 1.12ab uiii hea i formed" y the shaft 23,' a spindle or shaft 28 is employed which passes thru'thehollow shaft r17. Thi'sspindlehasattached to it at 'its outer end a ,lmob 29, which lies adjacent he ia 1 by m ils .Qf. w i l c e 'a ay be rotatkz d.' At the inner end of-the shaft 17a collar 30 attached toth e: spindle 28 which holds the said spindle proper position. ,lIpon the end-of the said'fs'indl is secured abe'velpinion31 which r'ries ies'with 'a.be vel gear 32 jsecuredto theshaft23 within the coil By rotating the knob 29 the coil, 12 may be turned ,upon [the I shaft 23 independent of it's rotation about the shaft In conn ecting the coil" 12 to the circuit the leads from said coil are directly soldered to the caps 27 positioned on the ends of the shaft 23. The arms 24 and 25 being of place.

th re e or.' a' oneto four ratio; 7 fe'ctn'e angle of rotation of the coil 12 is '90 degrees to bring said coil from. its posimetal make electrical contact with the caps 2-iand by attaching the terminalsof flexible conductors under the heads of screws 21 and 22 the connections of coil 12 may be brought to the panel 1().- It will be readily seen that by spreading the arms 24 and 25 apart, the coili12rmay be quickly removed from its support and another coil substitute-:1 in its ln this'manner any number of coils may be interchangeably mounted within the support consisting of the arms 2'1 and 25.

The form of the invention shown in Fig. 3 and in Fig. 4 differs mainly from that shown in Figs. 1 and 2 in that a different type of reduction gearing is employed and in the arrangement of the supporting arms. Here I employ two arms 33 and 34 which are imbeddcd in a block of insulating mate rial cast upon the end of the shaft 17.

These arms do not diverge like the arms 24 and 25 but run substantially parallel and engage the shaft 23 within the interior of the coil 12 as best shown'in Fig. 3. The ends of the arms 33 and 34 aresplit and arranged with forkedopenings 36 which are" adapted to slip over ferrules 37 mounted on the. shaft 23 so as to hold said shaftdet-achably mounted for rotation.

Instead of the bevel gears for operating the shaft 23, in this form of. the invention I use a worm- 38 which isattachcd to the end of the spindle 28 and meshes with a small trically positioned so that the aetual' center of'the coil proper comes substantially at the centerof the shaft 17.

The ratio of the gears for.rotating the shaft 23 may be any desired ratio but I have found it most practical to employ a one to Since the eftion of maximum coupling to its position of minimum coupling a one to four ratio perm ts of a 360 degree rotation of the knob .29 for the entire'range of the movement of the coil 12.

The operation of the invention will best be comprehended from an inspection of Figs. 3 and *1. Assumethat the coil 12 is to be arranged for a small amount of intercoupling with the coil 11.. The said coil would then be set as illustrated with the plane of said coil positioned almost at right angles to the coil 11. 'Say for example that this coupling was 10"2, of the maximum; \Yhcn the coil 12 placed as shown in full lines in Fig. 3 by rotating the dial 18. the maximum coupling obtainablewith the particular setting of the knob 29 is being had By rotating the dial 18 degrees the coil 12 will pling is being had.

take the position shown in dotted lines in Fig. 3 at which position the minimum coureadily seen that witlra 90 degree rotation of. the'dial only 10% of the entire range may be covered hence making the adjustment at loose coupling more refined and precise than with the ordinary form of coupler where the entire range is covered in a 99 degree rotation of the dial. When the maximum feed-back of the coil 12 as procuredby the knob 29is very slightit can be readily seen that the adjustment procured by the rotation of the dial 18 is almost micrometric. On the other hand when the coils 12 and 11 are set so that the coupling between them It can therefore be.

as secured by the adjustment of the knob?!) approaches the maximumwvhich takes place when the coils are closest. to being parallel then the adjustment had by rotating the dial- 18 is much coarser than may behad by the rotation of the knob-29alone..' Such adjust-- ment then is practically the same'as in the ordinary 'form of..varioeoupler.-:.Th1s arrangement meets with all the requirementsof t'eedeba'clr as-a. proper adjustment: is had at all wavelengths.- I 1 i In'Fig; 5 I have shown another method- & .ported'as follows: An arcuate plate72 of inof attaching-the arms of my invention to the shaft 17 thereof. The endof. shaft 17 is threaded ;for adistance along the samewhich is threaded upon its exterior. at Gland clamped upon the panel 10 by means of a nutGtZ; eA-collar 63:is pressed upon said shaft in spaced relation to the bushingtil, between which and a washer 6% a compression coil spring is positioned which serves to hold the dial- 1.8 in frictional engagement with the bush ng (30, thereby eliminating the spring 48., The end of the shaft 17 has socured to it a yoke'titi formed with arms 67 and 63- which take the place of arms 24 and 25, these arms being sin'iilarly constructed to the arms-33 and .34 of the form of the invention shown in Figs. 0 and 4. By employing ametallic shaft 69 instead of the shaft 23 the grooved portions 26 of the arms 67 and'68 directly; engage said shaft, thereby eliminatingthe ferrules 37. Uponthe ends of the shaft 69 are attached clips by means of which the coil 12 may be readily attached thereto. The. gear 32 is attached-to shaft 69 and meshes with the gear 31 which is -mounted on the end of the spindle 28.

..sulating material "such-as fibervis positioned as indicated fat'lt). 'Upon' this threaded por- 73 whiclrpassaround said. coil and are attion are placed-two nuts-41 and=-42:between which the twoarms I43I3Ild A l-are clamped.

Said armsyare' :kept electrically; insulated fromcach other. by means-'of-washers.45 and:

46 which are made-of fiber and which-sepfeeding the coi-l'= 12:: may be .condtict'ed ;thru the arms43 and lkasdesiredl-n .i'i'! F or'providing-the necessarys frictionbetween the various rotating parts crow foot springs47 and 48. may beemployedwhich may be inserted betweenthe knob- 29 a'ndthe dial 18;.- andbetween.- *the' -.dial. 18.-.-a'ndthe -'adjaccnt';the coil. 71, said =coil .being held attached therctoby means of two fiber-bands zutached to the plate 72 bymeanso'f bolts-.74: and -whichmay form the:binding. posts of the-coil if desiredi A metal angle-76 is riveted to the plate 72 and istormed with anzopenuended-slot77;.by means. of which 'the-same-.may bef=held inplace-upon the bushing 60.betweenthe-panel- 10 and .thelnnt 625-.1Vhl6hw: maygj be 4 tightened 1 against .:it.

-When itz-isfdesired to exchange ,or: remove :thefixedz coil them'esult is. easily accompanel 10. In Fig. 5 is shown another meth- 0d of producing the desired frict-ionbetween the knob 29 and the .dial 18;:zHere the interior of theshaft 17 is enlargedat 49 to receive a compression coil spring a50-which .bears againsta shoulder-51 formed-finthe shaft 17 and also against the collar 30 secured to the spindle 28.

In Figs.- 6, 'Z ands 8-1 have shown a form of the invention-which most nearly rescmbles that disclosed in Figs; 1 and 2.- The principal difi'erence, however, resides in the substitution of. a flat coil for the tubular coil and mounting it-from a single support. Also the leads to the movable coil have been taken directly from the same instead of thru the shaft 17 is journall'edina flanged bushing;

the entire coil unit=outu 3' plished-bydooseningthe nut- 62 and sliding Thejmounting-sh'omn--ini Figs-:6 and 7 mayals'o be used insupporting a tubular or-solenoid coil.'-= For thisipurpose an at taching" member 78 is used which is arranged with the slot 77 and which has two arms 79 Z?- sameniay be riveted onbolted thereto.

.The coil 71 shown in Fig. 7 may be formed with two or more separate windings ar- .-ranged-in fixed'relation to one another-and -wound to .form part of, the. sameeoil, pro

viding a primary and a secondary. If desired; theprimary and secondary maybe made separate, one of them being supported on a supporting angle 76, the same as'illustrated in Fig. 7, while the other could be supported on a device such as shown in Fig.

10. This structure consists of a plate 86 adapted to be clamped along with the angle 76 beneath the nut 62. A forked portion 87 is hingedly connected at 88 to the plate 86 and carries the coil proper in the same manner as angle 76 illustrated in Fig. 7. \Vith this arrangement, the coil so supported can be arranged in any inductive relation to the fixed coil and the movable coil giving a wide latitude in adjustment of the relative inductive coupling of the coils,

Altho I have' described my invention primarily as adapted to a varicoupler yet it can be readily understood that the same may be used as a variometcr or as any other tuning device employing a pair of coils be tween which the coupling may be altered at will. The method of using and connectin; up tuning devices of the nature of my invention being so well understood in the art I have not deemed it necessary to show wiring diagrams therefor or to otherwise describe the same in detail.

The invention may be used as a variable inductance, not only in the form of a variocoupler, but also as a variometer by conductively connecting the fixed and movable coils in the usual manner, said coils being provided in suitable inductance values for any given tuning circuit. utilized as a radio frequency transformer, or tuning unit, by utilizing the movable coil as the primary and the fixed coil as the secondary, or vice-veisa, said coils being provided of desired inductance value for any given'circuit.

In any circuit, receiving or transmitting,

my invention is adaptable by reason of its mechanical features to numerous variable uses because of the fine adjustmentspossible between the fixed and movable coils;

The principal advantage of my invention resides in that the coupling between the movable and fixed coils of my invention may be accurately adjusted over'the entire band of wave lengths so' that the signals may be picked up with greater ease andso that agreater number of stations may be timed in where employed in any given receiving circuit. The invention is exceedingly simple and is easily operated, there'being a minimum number of parts to get out of order; The two controls for the operation of the device being'concentrically mounted so as to be readily accessible and conveniently manipulated. f

Having described my invention in the form which I consider the best embodiment thereof, I desire to have it understood that the invention may be const-ructedin different forms and put to different uses within the scope of the following claims:

Claims 1! A radio tuning device for application It may also be to a fixed support comprising a coil mounted upon said support, a second coil arranged for rotation relative to said first coil about two intersecting axes, an operating member having a fixed situs relative to said support for rotating said movable coil about one of its axes, and another operating member having a fixed situs relative to said support for independently rotating said coil about its other axis.

2. A tuning device comprising a fixed coil, a hollow shaft rotatably mounted relative to said fixed coil a support carried by said shaft, a second shaft angularlv disposed relative to said first shaft and journalled in said support, a coil carried by said second shaft, a spindle passing through said first shaft and operating means connecting said spindle and second shaft for independently rotating said second shaft. 3

3. A tuning device comprising a bushing, a hollow shaft rotatable therein, a coil mounted on said shaft, for rotation relative thereto, a spindle passing through said shaft for rotating said coil, an abutment' on said, 90 hollow shaft engaging said bushing on one side, said spindle being frictionally restrained from free movement, a collar on said hollow shaft on the side opposite said abutment and spaced from said bushing, and a coilspring surrounding said hollow shaft and seated between said bushingand collar for creating a frictional resistance to said shaft in excess of that of'said spindle.

4. A tuning device comprising a fixed'coi]; 1 a shaft rotatably mounted relative to said fixed coil, a support carried by said shaft, asecon'd'shaft mounted in saids'upport, being positioned at right angles to said first named shaft, means for rotating said second shaft extending'thru said first named shaft alil df-a movable coil mounted upon said second s a t. I

i 5.- A tuning device comprising 'a-fixed coil, I

bushing, a nut screwable thereon, a shaft rotatable within said bushing, a coil 'rno'unted on said shaft, an angle plate removably attached to said bushing, and'a'coil secured to said angle plate.

7; "In combination with a panel a coil mounting comprising a bushing adapted to pass therethrough, a nut screwable upon the end of said bushing, an angle plate having an open ended slot adapted to pass over said bushing and a coil secured thereto.

8. k1 combination with a panel a coil mounting comprising a bushing adapted to pass therethrough, a nut screwable upon the end of said bushing, an angle plate having an open ended slot adapted to pass over said bushing, an arcuate insulating plate attached to said angle, a coil lying adjacent said plate and a pair of bands passing around said coil and secured to said plate for holding the coil attached thereto.

9. A tuning device comprising a fixed coil, a shaft rotatably mounted relative to said fixed coil, a support upon the end of said shaft comprising a pair of spaced arms, a second shaft, a coil mounted upon said second shaft, and means formed on the end of said arms for detachably supporting said second shaft for rotation relative to said first shaft.

10. A tuning device comprising a fixed coil, a shaft rotatably mounted relative to said fixed coil, a support upon the end of said shaft comprising a pair of spaced arms,

second shaft, said arms having resilient curved fingers formed on the ends thereof adapted to surround said second shaft for detachably holding the same in place.

12. A tuning device comprising a fixed planiform coil having a central opening, a shaft lying along said coil, a support attached to the end of said shaft, a second shaft angularly situated relative to said first shaft and journalled in said support, and a second coil attached to said second shaft, said second shaft, coil and support being revoluble within the opening in said first coil.

In testimony whereof I affix my signature.

WILLIAM L. MILLER. 

